0101

0101 is a single-player, mouse- and keyboard-controlled puzzle game.

There are three ways of playing this game and, though they all involve clicking numbers on the screen, they require different strategies. All game modes are timed and each has seventy-five levels with later levels being harder than the earlier ones:

• CLASSIC: In this mode the player is shown a grid of zeroes and ones. Clicking on one cell in this grid causes it and the numbers above, below, left, and right to change state with zeroes changing to a one and ones changing to a zero. The aim is to change all the cells in the grid to a zero.
• PUSHER: In this game, the player is shown a series of single-digit numbers and must type the sequence on their keyboard correctly within the time limit.
• COUNTER: As with PUSHER, the player is given a sequence of single-digit numbers but this time the player has to click on each number until it is reduced to zero. If the player clicks too much the number becomes negative and the game is over.

There are no in-game instructions so be sure to read the official game description before starting.

The game does not automatically move to the next level once it has been completed, the player is returned to the main menu where they can select a level from the menu. When a level is replayed the patterns and sequences are different. The game records the completion time for each level.